Recently, with the increasing shortage of the world's energy supply, the development and utilization of wind energy, solar energy and other renewable energy attract much attention. But the efficient, cheap, safe and reliable energy storage technologies must be combined with the renewable energy in order to ensure the steady power supply of solar, wind and other renewable energy power generation systems. Among various energy storage technologies, the flow energy storage battery, one chemical energy storage method, becomes one of the most suitable batteries for large-scale energy storage at present because of unique advantages.
Now, two kinds of well-developed flow battery systems are vanadium flow battery and zinc bromine flow battery. The vanadium flow battery realizes the reversible conversion between the chemical energy and electric energy by an electrochemical reaction of vanadium ions with different valence states in the electrolyte on an inert electrode. The positive and negative redox couples are VO2+/VO2+ and V2+/V3+ respectively. The sulfuric acid acts as a supporting electrolyte. Because of the vanadium ions with different valence states on the positive and negative sides, the contamination caused by the movement of each other to the electrolyte is avoided and the battery performance and life are improved. In addition, a vanadium electrolyte can be easily recovered, thereby further improving the life of a battery system and reducing operating costs. But the electrolyte cost of the vanadium flow battery and the cost of a proton exchange membrane are relatively high, and a certain cross contamination problem exists in the positive and negative electrolyte.
The positive and negative half-battery of the zinc bromine flow battery is separated by a separator, and the electrolytes on both sides are ZnBr2 solution. Under the action of a power pump, the electrolyte conducts circular flow in a closed loop composed of a reservoir and a battery. The main problem that the zinc bromine flow battery exists is the bromine contamination.
The quinone bromine flow battery has been reported in a literature, but since a proton exchange membrane is used in the literature, and the sulfuric acid is used as the supporting electrolyte, the cost and battery voltage are low. The present invention uses a porous membrane and uses the hydrochloric acid as the supporting electrolyte, so that the cost is reduced while the voltage is increased.